1. Field of the Invention
The present invention concerns an implement coupling for a loading machine.
2. Description of the Prior Art
Implement couplings for a digging or loading machine are used for the purpose of rapidly and easily changing between different implements, e.g. between loading buckets with different widths or different capacity. The implement coupling may include a manually operated changing mechanism requiring that the machine operator leaves the operator""s cabin, or may comprise a remotely controlled changing mechanism that may be operated from the cabin and which, for example, may comprise a hydraulic cylinder.
The invention has the purpose to provide an implement coupling for a loading machine which by means of simple measures enables achieving good function and extraordinary safety against unintended release of the implement.
The implement coupling according to the invention is peculiar in that the coupling means are constituted by upper fixed hook coupling parts, which are arranged for gripping around upper connecting pins on the implement, and by lower, displacing hook coupling parts, which are arranged for fixing lower connecting pins of the implement when the lower connecting pins are in contact with a contact surface on the implement coupling, the displacing coupling parts being connected with the locking beam. By means of simple technical measures there is achieved good function of the implement coupling and extra safety against release of the implement caused by unintended deactivation of the locking function of the implement coupling. It is to be emphasized that the design of the complementary coupling of implement and implement coupling counteracts difficulties due to relatively often occurring variations in spacing between coupling parts of the implement coupling and connecting pins on the implement.
Suitably, the implement coupling according to the invention may comprise a pivot mechanism arranged to displace the locking beam via a connecting arm, wherein the pivot mechanism comprises an actuation member which is pivotably suspended in the implement coupling, and which is arranged to be pivoted by means of either a mechanical spindle or a hydraulic cylinder, and that the pivot mechanism furthermore is connected with a strong compression spring arranged to bias the locking beam towards a locking position thereof with a pressing action.
When the implement coupling according to the invention is adapted for manual operation, it may suitably include at least one mechanical spindle arranged to cause displacing of the locking beam, wherein the locking beam is also connected with a strong compression spring arranged to exert constant pressure on the locking beam so as to bias the beam towards its locking position.
When adapted for hydraulic operation, the implement coupling according to the invention may advantageously include at least one cylinder arranged to cause the displacing of the locking beam, wherein the locking beam furthermore is connected with at least one strong compression spring arranged to exert constant pressure on the locking beam so as to bias the locking beam towards its locking position.
The implement coupling according to the invention may furthermore advantageously be adapted to include a hydraulic cylinder disposed at the center of the implement coupling and arranged to cause the sliding of the locking beam.
Alternatively, the implement coupling according to the invention may furthermore include two hydraulic cylinders disposed at each their end of the implement coupling and arranged to cause the displacing of the locking beam.
Furthermore, the implement coupling according to the invention may be designed so that the contact surface of the implement coupling at the side facing the fixed hook coupling part is provided with a projection for facilitating temporary connection between implement coupling and implement until final locking engagement has occurred.